rooperi's solution of course works for two rooks as well, and an alternative way to check the king with two queens would be to replace the black rook with a queen in the OP's position, removing at least one black pawn.
Legal or Illegal (yes I know it's old!)
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shoopi wrote:
TBentley wrote:
This reminds me of a position I saw in Jeff Coakley's "The Puzzling Side of Chess" column:
That looks illegal.
The only last moves could have been g4 and fxg3ep.
So white's b7 bishop is promoted. The promoted pawn must be the f2 pawn.
Black has two promoted pieces, a rook and the d1 bishop. the b7 and c7 pawns have enough white pieces to capture to achieve that. However, that leaves black with only one available piece to capture, a light square bishop.
The only way white's f2 pawn can promote using only one capture, is fxe7. However e7 is a dark square, therefore black's light square bishop cannot be used for that, therefore illegal.
Well done.
Ops! in the last position the last move could have been Nd1 - f2+.
I fixed it now. Legal or illegal? (hint: it's not that easy...)
shoopi wrote:
Here's one for ya. Legal or illegal?
Illegal. How can the Black King be in check on the first rank if the checking piece (the Rook) can't have checked him because the Knight is blocking the F file?
adamplenty wrote:
shoopi wrote:
Here's one for ya. Legal or illegal?
Illegal. How can the Black King be in check on the first rank if the checking piece (the Rook) can't have checked him because the Knight is blocking the F file?
White's last move was 0-0
rooperi wrote:
adamplenty wrote:
shoopi wrote:
Here's one for ya. Legal or illegal?
Illegal. How can the Black King be in check on the first rank if the checking piece (the Rook) can't have checked him because the Knight is blocking the F file?
White's last move was 0-0
I knew there was something. What's wrong with me? That's twice I've overlooked something simple 
. The position looks fine to me now.
adamplenty wrote:
rooperi wrote:
adamplenty wrote:
shoopi wrote:
Here's one for ya. Legal or illegal?
Illegal. How can the Black King be in check on the first rank if the checking piece (the Rook) can't have checked him because the Knight is blocking the F file?
White's last move was 0-0
I knew there was something. What's wrong with me? That's twice I've overlooked something simple . The position looks fine to me now.
Oh, I can bet you shoopi's got a few twists hidden in there :)
rooperi wrote:
adamplenty wrote:
rooperi wrote:
adamplenty wrote:
shoopi wrote:
Here's one for ya. Legal or illegal?
Illegal. How can the Black King be in check on the first rank if the checking piece (the Rook) can't have checked him because the Knight is blocking the F file?
White's last move was 0-0
I knew there was something. What's wrong with me? That's twice I've overlooked something simple . The position looks fine to me now.
Oh, I can bet you shoopi's got a few twists hidden in there :)
I've looked and I can't see anything wrong with it. Unless I'm again overlooking something simple? 
Attention: my post has been edited!
And rooperi is right.
(Double post by mistake)
Are you telling us the answer, that's it's illegal? 
White's last move could have been Nf2 or O-O. White is missing the light squared bishop, and the rook, the latter of which was captured on f6 before black's bishop got out. White played f4 before the rook was captured, so black's bishop moved Bh6-g5-h4-e1... or by Bh6-g5-h4-g3-h2-g1... but then the e pawn would not have moved so the king had to move so the rook could get out, so white's last move cannot have been O-O. I wrote this post while Nf2 was legal, I don't believe the situation's changed, so it would be illegal.
The pawn on f6 must have capture a white Rook. Can you figure out how that happened, adam?
TBentley wrote:
White's last move could have been Nf2 or O-O. White is missing the light squared bishop, and the rook, the latter of which was captured on f6 before black's bishop got out. White played f4 before the rook was captured, so black's bishop moved Bh6-g5-h4-e1... or by Bh6-g5-h4-g3-h2-g1... but then the e pawn would not have moved so the king had to move so the rook could get out, so white's last move cannot have been O-O. I wrote this post while Nf2 was legal, I don't believe the situation's changed, so it would be illegal.
The man is right, castling is impossible, therefore illegal!
So I was right, but for the wrong reasons?
By the way, original was legal, well done those who solved it. I saw a similar position which could have occured on TT and thought it would make an interesting problem.
Just figured it out, then saw it was already answered. So here it is in my words:
The white rook was captured on f6. In order to get it there without moving the king, the moves d3, e3 and f4 had to happen. Before the capture, the bishop on f8 couldn't move, and after it the bishop could never move to a7 because the pawns e3 and f4 were already there. So the king did move, and castling would have been illegal, so this position is impossible.
Gwilym stem
My 1st one.
the position is legal since, see the sequence of moves that makes it possible agreeing with Elubas
Didn't think of that!